Technical renovation for gas-water separation and dust-containing tar separation and recovery in coal-to-gas production at Datang Keqi

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Technical Transformation for Gas-Water Separation and Dusty Tar Separation and Recovery in Datang Keqi Coal-to-Natural Gas Project. Author/Source: Datang Keqi Coal-to-Natural Gas Company. Date: July 16, 2021. Clicks: 23. In June 2021, the gas-water separation and two-phase separation recovery technical transformation project carried out at the gasification center of Datang Keqi Coal-to-Natural Gas Project was fully put into operation. To date, it has achieved the positive result that dusty tar from all four categories is not sold externally; the by-product tar that is sold can generate an annual income increase of over 19 million yuan, based on cost-benefit analysis and market prices. On April 29, 2020, the newly revised Law on the Prevention and Control of Environmental Pollution by Solid Waste was passed, with its implementation set to begin on September 1. Among these, the dust-containing tar generated in the gas-water separation section of the gasification center was classified as hazardous waste. Consequently, its selling price plummeted for a time, exerting certain effects and impacts on the company’s production and operations. Faced with the severe challenges in the new situation, the company shifted its mindset further, focusing on energy conservation and reduction of consumption. The gasification center responded promptly by making early arrangements; by emphasizing innovation and efficiency, it tapped into its full potential. In June 2020, a feasibility study report for a technical upgrade project related to dusty tar was prepared, thereby driving continuous improvements in quality and efficiency. With the care and guidance of the company’s leadership and the strong support of various departments, the Gasification Center quickly established a special team for innovation and problem-solving. It successfully completed the preliminary research, feasibility studies, initial design, and other related tasks. Adhering to the principle of making use of existing resources to reduce expenses, the center installed and put into use a two-phase horizontal centrifuge previously used for decoking at the Utility Engineering Center, thus enabling the preliminary work to progress in an orderly manner. Everything is difficult at the beginning. Faced with all the unknown aspects of innovative technological upgrades, the complex structure of the equipment, and various production conditions in actual operation, there are no established procedures to follow, nor any precise parameters for accurate control; all that exists is the unity and determination of all the employees working together as one team. Once all preparations were complete, preliminary testing and operation took place from August 21 to September 4, 2020. Through five repeated trials, although some issues were identified, the feasibility of implementing the technical upgrades was confirmed, which further strengthened confidence for subsequent trial operations. Through continuous refinement and error correction in practice, as well as the readjustment of the data, centrifugal separation tests on dust-containing tar at the gasification center were officially conducted on September 29, 2020. The gasification center organized meticulously and deployed resources thoroughly, using a \"determined perseverance\" to overcome one challenge after another and surmount various difficulties, ultimately achieving the desired results in terms of separation. Cost savings. When dust-containing tar discharged intermittently accumulates in large quantities within the equipment, it can easily cause damage to the agitator of the primary tar separator; this occurs on average about 5 times per year, and there are numerous safety risks associated with the maintenance process. Improve the environment. The original external loading pipeline failed to be sealed, resulting in the emission of unpleasant odors and the splashing of tar, which often caused environmental pollution such as contamination of the floor. Increase automation. The original loading process required at least two people to work together; after the technical upgrades, the automation of the equipment has been increased, reducing the workload for staff and improving working conditions. Improve quality and efficiency. Dusty tar is difficult to store and transport due to its high solid content and viscosity. Separating dust and tar from dusty tar can significantly increase the revenue from by-product sales.